DC1778B-A: 1.8V @ 20A, 6.5 ~ 24V in, Buck

Summary

Demonstration circuit 1778B-A is a single-output, synchronous buck converter featuring the LTC3883EUH, a single-output current mode controller with digital power management and input current sense capability. It senses output inductor current across a sense resistor.

The board can be populated with the LTC3883EUH-1, which allows the user to provide bias power to the IC from an external power supply to save on-board LDO power loss.

The output voltage of the board can be programmed from 0.5V to 5V, with output current up to 20A. The factory default setting for the output is 1.8V.

The DC1778B-A powers up to default settings and produces power based on configuration resistors, or NVM, without the need for any serial bus communication. This allows easy evaluation of the DC/DC converter aspects of the LTC3883. To fully explore the extensive digital power management features of the part, download the LTpowerPlay® GUI software onto your PC and use LTC’s I2C/SMBus/PMBus dongle DC1613A to connect to the board. LTpowerPlay allows the user to reconfigure the part on-the-fly and store the configuration in EEPROM, view telemetry of voltage, current, temperature and fault status.

Specifications

Manufacturer	Analog Devices Inc.
Category	AC/DC and DC/DC Conversion
Sub-Category	DC/DC SMPS - Single Output
Eval Board Part Number	505-DC1778B-A-ND
Eval Board Supplier	Analog Devices Inc.
Eval Board	Board not Stocked
Topology	Step Down
Outputs and Type	1 Non-Isolated
Voltage Out: Factory Set	1.8 V
Current Out	20 A
Voltage In	6.5 ~ 24 V
Efficiency @ Conditions	>90%, 12V in, 1.8V @ 9 ~ 20 A >89%, 12V in, 1.5V @ 8 ~ 20 A >88%, 12V in, 1.2V @ 8 ~20 A >86%, 12V in, 1.0V @ 9 ~ 20 A
Voltage Out Range	0.5 ~ 5 V
Features	Current Limit (Adj. or Fixed) I²C Interface Memory Available On-Board PMBus Interface Power Good Output Shutdown, Enable, Standby Soft Start Synchronizable Temperature Compensation Under Voltage Protection, Brown-Out
Switching Frequency	425 kHz
Standby Current [Typical]	- Not Given
Quiescent Current [Typical]	20 mA
Component Count + Extras	92 + 42
Internal Switch	No
Design Author	Linear Technology
Application / Target Market	Power: Auxiliary Power Supply Telecom
Standby Current [Maximum]	- Not Given
Quiescent Current [Maximum]	30 mA
Main I.C. Base Part	LTC3883
Date Created By Author	2012-05
Date Added To Library	2016-12